In recent years increasing numbers of municipalities, office complexes, shopping centers and other commercial developments have utilized thermoplastic pavement markings with various patterns and designs to guide, decorate and protect high traffic areas such as highways, pedestrian crosswalks, parking lots and business entrances. A typical, conventional pavement marking pattern as set forth in PCT application US/03/03156 (WO03/064771 A1) consists of a preformed planar thermoplastic sheet or strip having a thickness of approximately 0.01″ (2.5 mm). The width of these patterns vary with the purpose of the marking Such patterns may include a first section or grid, for example to represent the mortar joints in a “brick” design and a plurality of second sections or “bricks” which are coplanar therewith, usually in a color different from the mortar color. The second section or bricks which are separately manufactured are inserted into the first section or grid before application of the pattern to the pavement. Various such two section marking patterns are commonly available such as: herringbone, standard brick, cobblestone, paving slabs and many other designs. Marking patterns with more than two sections are also commonly available such as horizontal highway and street signage, logos and many others.
As hereinbefore mentioned, these marking patterns consist of two or more independent sections which must be carefully assembled and handled before applying to pavements such as asphalt, concrete or other suitable substrates. These marking patterns are placed at desired locations such as road crosswalks, intersections, parking lots or other sites. In some cases heat is then applied to soften the pavement marking pattern causing it to firmly adhere to the substrate. Various adhesives can also be used to adhere the marking pattern to the substrate.
While the purchase of such pavement marking patterns is relatively inexpensive, much time and labor is devoted to the assembly and application of the pattern to the substrate. Most patterns consist of two or more sections which are independently formed for manual assembly at the job site and time and effort is needed to assemble and maintain the integrity of a pattern before the heat treatment. Usually the pattern placed on the substrate must be moved manually for adjustment purposes. During such movement, the independent sections in the pattern inadvertently become unaligned, requiring reinsertion or realignment. If the realignment is not precisely accomplished, the marking pattern will have lost its integrity and the entire pattern must be removed manually from the substrate, the substrate cleaned and a second attempt at the application made with the reinserted or new marking pattern. This re-application results in extra time, labor and materials. In the past, to maintain the integrity of the marking pattern before the heat treatment and during the handling and placement, “spot adhesives” have been used which remain somewhat “tacky” after being applied to the bottom of the patterns at the grid intersections to maintain pattern integrity. However, these small adhesive circles or “spots” are generally a different type of polymer than the marking pattern and can prevent proper attachment and easy movement of the marking pattern on the substrate at the spot adhesive locations before and during the heat application of the marking. Also, certain spot adhesives are not compatible with the plastic materials from which the patterns are formed and can cause the pavement marking sections to separate from the substrate after the heat application, as only a weak bond is formed with the substrate.
Thus with the problems and difficulties associated with maintaining the integrity of the pavement marking patterns during handling and application at the job site, the present invention was conceived and one of its objectives is to provide an improved pavement marking pattern in which the pattern sections are properly connected during handling and installation on a selected substrate. It is another objective of the present invention to provide a relatively inexpensive pavement marking pattern having two or more sections in which the sections are joined by use of an applied adhesive.
It is yet another objective of the present invention to provide a method for forming a pavement marking pattern which allows cost efficient factory assembly of the pattern and which prevents dislodging and separation of the pattern sections during handling, transportation and application.
It is still another objective of the present invention to provide an adhesive which can be conveniently sprayed onto the back of pavement marking patterns which will sufficiently adhere thereto and prevent separation of the sections during handling, and not deteriorate the bond between the pavement marking pattern and the substrate.
It is still another objective of the present invention to provide a method for easy application of the adhesively sprayed marking pattern to the substrate.
Various other objectives and advantages of the present invention will become apparent to those skilled in the art as a more detailed description is set forth below.